package java6.src.chapter10.login;

import java.sql.*;
import java.util.Scanner;

public class login {
    public static void main(String[] args) throws SQLException {
        Statement stmt = null;
        ResultSet rs = null;
        Connection conn = null;
        try {
            // 1.注册数据库的驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            // 2. 通过DriverManager获取数据库连接
            String url = "jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8&useSSL=false";
            String username = "root";// 数据库账户
            String password = "123456";
            conn = DriverManager.getConnection(url, username, password);
            /**
             * 终端用户登录
             * 不绑定数据使用conn.createStatement()
             * 绑定数据使用 conn.prepareStatement()
             */
            Scanner sc = new Scanner(System.in);
            System.out.println("用户登录");
            System.out.println("请输入你的姓名:");
            String userName = sc.next();
            System.out.println("请输入你的密码:");
            String userPwd = sc.next();
            String loginSql = "select * from users where name=? and password=?";
            PreparedStatement pm = conn.prepareStatement(loginSql);
            pm.setString(1,userName);
            pm.setString(2,userPwd);
            rs = pm.executeQuery();//executeQuery返回多行数据 executeQuery()返回一个int
            System.out.println("id  |   name   |   password    |   email    |   birthday");
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getNString("name");
                if (id>0){
                    System.out.println( name +"登陆成功 ");
                    // 如果数据库中有两个同名同密码的人 直接结束循环 只提示第一人
                    break;
                }
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            // 6.回收数据库资源
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                rs = null;
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                    stmt = null;
                }
                if (conn != null) {
                    try {
                        conn.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                    conn = null;
                }
            }
        }
    }
}